LONDON: British astronomers have found out the answer to an astronomical mystery — how do galaxies die? Evidence shows that they are “strangled to death”, which occurs after galaxies are cut off from the raw materials needed to make new stars.
There are two types of galaxies in the Universe: roughly half are “alive” galaxies which produce stars, while the other half are “dead” ones which don’t.
Alive galaxies such as the Milky Way are rich in the cold gas — mostly hydrogen — needed to produce new stars, while dead galaxies have very low supplies, Xinhua news agency reported.
Previous studies have come up with two main hypotheses for galactic death: either the cold gas needed to produce new stars is suddenly “sucked” out of the galaxies by internal or external forces, or the supply of incoming cold gas is somehow stopped, slowly strangling the galaxy to death over a prolonged period of time, according to the report recently published by the Journal Nature.
To answer the question, researchers from the University of Cambridge and the Royal Observatory Edinburgh used data from the Sloan Digital Sky Survey to analyze metal levels in more than 26,000 average-sized galaxies located in our corner of the universe, according to the report.
